Hi - in PT 2019, how does one insert an effect on part of a track only? I'm trying to do it with AudioSuite, but I get a message saying "no audio selected" even though I have highlighted the section I want to have the effect on, and armed record. Any ideas? Thanks!

Audiosuite is offline. You don't arm or record. You select a region and render and a new file is written over the top.

An insert plugin (AAX) is online. You insert it on the track itself. Once again you don't arm and record. You automate a bypass if you only want a region affected using automation. That can be done with automation record if you want.

This isn't a PT2019 thing. This is how pro tools has worked from almost the beginning.

If the effect is time-based(reverb, delay), its probably better to send to an AUX track>insert the effect on the AUX track and automate the send Automating Bypass is fine, but with reverb or echo, the bypass will kill the effect abruptly(maybe not what you want)